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<div>Rectangle1:</div>
<div>$$ \begin{align}
  LENGTH &= 11cm \\
  WIDTH &= 20 - 10 = 10cm\\
  AREA &= 11 \times 10 = 110cm^2
  \end{align} $$</div>
<div>Rectangle2:</div>
<div>$$ \begin{align}
  LENGTH &= 10cm\\ WIDTH &= 20cm\\
  AREA &= 10 \times 20 = 200cm^2
  \end{align} $$</div>
<div>Add together the areas:</div>
<div>$$ AREA = 110 + 200 = 310cm^2 $$</div>
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